Three workers demonstrating the different types of gas masks used in mine rescue work. (Photo by Fox Photos/Getty Images). December 1925

A U.S. soccer fan pretends that Uruguay's soccer striker Luis Suarez is biting him as he takes a selfie next to an Adidas advertisement featuring Suarez near Copacabana beach in Rio de Janeiro, Brazil, Thursday, June 26, 2014. FIFA banned Suarez from all football activities for four months on Thursday for biting an opponent at the World Cup, a punishment that rules him out of the rest of the tournament. (Photo by Matt Dunham/AP Photo)

Thomas jumps into the water from a spring board at a public swimming pool in Mengen, Germany, 28 August 2016. (Photo by Thomas Warnack/EPA)

A photo taken on July 22, 2017 shows beach- goers dancing at the West Sea Barrage beach outside the coastal city of Nampo, southwest of Pyongyang. The West Sea Barrage beach features as a stopping point for foreign tourists, and is a destination for North Korean work groups from the neighbouring area. The beach lies at the end of an eight- kilometre- long barrage that separates the sea from the Taedong River, which runs through Pyongyang. (Photo by Ed Jones/AFP Photo)

Soldiers of the 70th division of the American 7th Army hold up a Nazi flag and a portrait of Adolf Hitler, taken during the World War II capture of Saarbrucken. (Photo by Horace Abrahams/Keystone/Getty Images). 22nd March 1945

Street entertainer and fortune teller “Juana La Cubana” smiles holding a cigar in her mouth as she waits for tourists in Havana, Cuba, Sunday, May 24, 2015. Juana is 72 years old and has worked in the Cathedral square in Old Havana for 28 years. (Photo by Desmond Boylan/AP Photo)

Bronze whaler shark (Carcharhinus brachyurus), caught in traditional seine net and released by fisherman, Muizenberg beach, Cape Town, South Africa on October 11, 2016. Action shots have captured fishermen trying to free a potentially deadly Bronze Whaler shark who was caught in their nets. The incredible images show the eight-foot-long 500-pound predator lunging its mouth towards the fishermen who are desperately trying to pull it back into the safety of the sea by its tail. Eventually they succeeded. (Photo by Chris and Monique Fallows/NPL)

A mahout bathes his elephant in the river Sabarmati on a hot summer day in Ahmedabad, India May 21, 2017. (Photo by Amit Dave/Reuters)